Thermostat



Oct. 20, 1936, R. L PARSQNS 2,057,967

THERMOSTAT Filed Sept. 4, 1934 III ,O f l 3l 4 n @la 1. 59 @93 f4@ 35 sa 2 -T :h 'KNMI A 15"@ 14 57 i l \Mi'3 Z5 \6 'C' 4 47 QQZO4 :aL/#n A7 54 /3'2 M .46 @J2 55 L iae 38 ZAI AO INENTOR m40-4J Patented Oct. 20, 1936 UNITED STATES PATENT OFFICE Aplzolication eptember 4, 193:4, Serial No. 142,546

6 (Gl. 20o-140) This invention relates to thermostats, more especially to a thermostat embodying a temperature 'responsive fluid, and particularly 4to a thermostat having an element of the vbellows type responsive to changes in pressure.

A principal object of this invention isto produce a device of the type speciiled which will be compact, easy to adjust, simple and inexpensive v to manufacture, particularly free from a tendency to get out of-order, very sensitive in its response to changes of temperature, and certain and powerful in its action. v

-Other objects and advantages will appear as the description of thek particular embodiment selected to illustrate the invention progresses, and

` the novel features will be particularly pointed out in the appended claims.

In describing the invention in detail and the particular physical embodiment selected to illustrate the invention, reference will be had to the accompanying drawing and the several views thereon, in which like characters of reference designate like parts throughout the several views,

and in which:

Figure 1 is a vertical sectional view of a panel with a thermostat oi applicants invention in place thereon, parts being shown in elevation; Fig. 2 is a cross-sectional view of the device on the plane indicated by the line II-II of- Fig. 1, Fig. 3) viewed in the direction of the arrows at the ends of the line; Fig. 3 ls a fragmentary, detail view in vertical section of the device on the plane indicated by the viewed in the direction of the arrows at the ends of the line; Fig. 4 is a vertical section of the device on the plane indicated by the line IV-IV of Fig. 2, viewed in the direction indicated by the arrows at the ends of the line.

In the iigures, numeral I designates a panel or mounting member upon which applicants device may be positioned. This panel may be made of any suitable material and in the instance illustrated is made of insulating material, as is usual.

Attached to the panel I, preferably by means of bolts, as 2, is a collar 3, having a flange I with apertures 5 to receive the bolts 2. Within the bore B of this collar is iitted an elongated tube 1, of suitable material, preferably metal, as in the instance illustrated, and having a lower closed end 8, the upper end of the tube having an open mouth 9 surrounded by an integral lip or flange III, of suitable size to lit snugly Within a recess I I provided for that purpose in the upper face of the ilange l.

Within the tube 1 is positioned an elongated line III- III of Fig. 1.

collapsible bellows elementl I2. which is assembled with the tube 1 and collar 3 by means of a flange i'which, as shown, is substantially of the same dimensions as that .of the ange 4 and exl tends over the lip or iiange III of the tube, in contact therewith, so that when the bolts 2 are tightened. a fluid tight joint is formed between the mouth ilanges IIl and Il. A gasket I4 is preferably provided between the ilange I3 and the panel I, 'to obviate any cutting action upon the ilange I3 by the contiguous edge Il of an aperture I6,

provided in the panel for a purpose to be described.

' The bellows structure or element I2 is preterably substantially co-extensive in length, in its expanded state, as shown, with the surrounding tube 1 and is of suitable diameter to nearly ll the chamber I1 formed between the inner walls I8 of the tube and the corrugated exterior walls I9 of the bellows.

This chamber is adapted and intended to receive a suitable temperature responsive fluid (not shown) such as glycerine as usual, and the chamber serves as a :duid-pressure chamber, any rise in the temperature of the enclosed fluid exertinga collapsing force lengthwise upon thev bellows.

Within the bellows I2 is provided a rod 20 the inner end 2| of which is positioned in the path of the axially moving bottom of the bellows, which may be desirably formed with a member 22 which serves as a closure and also as a reinforcement for the inner end of the bellows, and as an abutment to resist the wear exerted by the inner end 2I of the rod, the latter being preferably rounded, as illustrated, to reduce such wear.

The rod 20.is of sufficient length to project, at its upper' end, 23, beyond the mouth of the bellows, through an aperture 24 in the gasket I4, and extends VYup through the panel aperture I6, which is provided to accommodate such projection ofthe rod.

'The tube1, bellows element I2, and rod 20, with their associated mounting and assembling parts above described, act, incooperation with the temperature responsive iluid in the lluld -pressure chamber I1, as a thermostat of sturdy constructhe collapsing movement lengthwise of the bellows being transmitted to the rod 20, which is moved bodily along its major axis,` and this movement may be translated usefully by suitable means provided in the path oi' the upper projecting end 23 of the rod. i y

This arrangement of thermostat at one side of the panel lends itself to the provision on `the other side ci' any suitable device intended to be operated by the thermostat, and it will be noted that the thermostat constitutes a self-contained, unitary structure. capable of combination with a variety of different devices, as well as interchangeably with any of a series of devices of similar, standard structure, designed for such interchangeable use.

As an illustrative example of a useful application lof the thermostat above described, I have shown in the drawing an electrical-circuit-controlling switch mounted upon the panel i. and adapted to be opened by upward movement of the rod 23 upon a rise in temperature of the fluid in chamber l1, accompanied by collapsing reponse of the bellows l2.

The switch structure comprises a metal frame having a base 2l' secured to the panel by the threaded end 25 of one of the bolts 2, which is screwed intoa threaded aperture 26 of the base 2l', and the base is similarly secured by other bolts 21 passing through the panel i and screwed into suitable portions of the base, which is L- shaped, as best seen in Fig. 4.

From one leg of the L-shaped base extends upward a forked bracket 26, the arms of which are traversed by a pin' 26 secured in place by a cotter electrical contact with a cooperating contact stud 36 mounted on a post 35 which has a foot 36 secured to panel I by screws 3l passing through the panel from beneath. The base has a terminal binding post or screw 36 ,to which can be connected one conductor C of the electrical circuit to be controlled by the switch. A suitable terminal plate 40 facilitates this connection and another conductor C of the electrical circuit is shown as nnected by a similar plate 46 and binding screw l2 to a lug 43 formed integrally with the base 2l. The base and all metal parts associated with it, including the various elements of the thermostat, are therefore grounded to one conductor of the circuit. The first named conductcr C, and terminal 36 are insulated, by the material of panel I, from the base, etc., when the contacts 33 and 34 are separated by upward swinging movement of the finger 32 into the dotted line position shown in Fig. 4.

The switch lever 3| and finger 32 are normally biased toward this circuit breaking position by the coil spring u, which is held under compression between the base 2l' and switch lever 3|, being ntted at'its lower end in a base socket 45 and at its upper end upon a lug 46 depending from the lower face of lever 3|. A push-button Il of insulating material, mounted on an offset lug 48 of the lever 3|, may be used to depress the lever 3| and finger 32 manually to complete the electrical circuit at n, u.

iigures, the illustrated means taking the form of a latch 46 fast upon a rock shaft 5U which is mounted rotatively in uprights 5| and 52 of the frame and around which is coiled a spring 53 which biases the shaft 53 in a counter-clockwise direction (see Figs. 1 and 2). This causes an upright hook 54, forming part of the latch, to engage a lug 55, offset from the switch lever 3l, and to hold the lever 3| and finger 32 in their depressed full line position, to maintain the contacts 33 and 3l in their circuit-closing position. The latch I6 is formed with an integral linger 56, which extends into proximity to the path of the rod and is adapted to be engaged with a collar 5l secured upon the rod and which is adapted to turn the latch in clockwise direction, against the bias of coil spring 53, and thus release the switch lever 3|, when the rod 20 is moved upwardly by collapsing action of the bellows I2. upon a sufficient rise in temperature of the uid in chamber Il, and a corresponding development of pressure adapted to collapse the bellows.

When the temperature of the fluid in chamber il falls, and the collapsing pressure on bellows i2 `therefore fails, there is a natural tendency of the bellows structure to assume its extended position, owing to the resiliency of the corrugated walls ii', as usual, the bellows is made of a resilient metal. 'I'he action of coil spring 53 thereupon tends to vdepress, the arm 56 and restore the lock 54 to its upright position, ready to engage and hold the switch lever 3l and spring linger 32 1n lull pin 3l and which serves as a pivot for a switch lever 3|, the latter having a spring contact linger 32 witha button 33 adapted to make and break' line position, maintaining the contacts 33, 3l in closed' circuit position when the push button 4l has been operated manually for this purpose.

While the weight of rod 2|), and the downward bias of arm 56, under the above described action of spring 53, is ordinarily sufficient to cause the rod 20 to follow the bottom 22 of bellows l2 as the latter expands, I prefer to provide an auxiliary means tending to bias the rod 20 downward, and to aid in expanding the bellows i2, and for this purpose have shown a coil-spring 53, mounted between an overhead bracket 59 of the frame upright 52 and the rod collar 51, which latter has an upright annular boss 60 within which the lower end of spring 53 is seated, surrounding the upper end 23 oi the rod. 'I'his end may desirabiy be threaded to afford a seat on which the collar 51 may be screwed to adjust the same and thereby 'to regulate the tension of spring 58. A set screw 6I serves to hold the collar 5l in adjusted position.

The bracket 53 may be recessed, as at 62, to seat the upper end of the spring 58, and may lbe strengthened by a web 63. It is also provided with a pin 6l, to limit the upward swing of the switch lever 3| and spring finger 32. This finger is preferably fastened securely to the arm, as by rivets 65, and in general provision is made for securing the parts of the switch in rigidly assembled relation wherever that is desirable. The bolts 2 are of sturdy structure, and the left-hand bolt is provided with a strong retaining nut 66, with washers 61 adapted to protect the insulating material of which panel is composed.

It should be noted also that the various working parts are biased independently by the action of individual springs, so that there is no possibility of lost motion in any position, whether operative or inoperative. This aids to promote sensitive. rapid and sure response to operative impulses, and prevents rattling of the parts when the device is associated with a vibrating structure, or one exposed to shocks in use.

Although I have particularly described one particular physical embodiment and explained the operation, construction and principle thereof, nevertheless, I desire to have it understood that the form selected is merely illustrative but does not exhaust the possible physical embodiments of the idea of means underlying my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. In a thermostat, in combination: a thinwalled metal tube having a closed end and an open end with a radial peripheral flange; a tubular, bellows-type pressure-responsive structure within said tube, having a closed inner end and an open end with a radial peripheral flange superimposed upon said tube ilange; a separately formed collar of heavier material, having a hollow boss within which the open ends of said tubular members are disposed and having a broad flange upon which said tubular flange and bellows flange are superimposed radially in the order named; means to secure said flanges together in iluid-tight assemblage, whereby a iluid p-ressure chamber is formed between the inner walls of said tube and the exterior walls of said bellows, said chamber being adapted to receive a temperature responsive fluid which serves to exert a lengthwise acting collapsing force upon said bellows structurewhen the temperature of said iluid rises; and a rod within said bellows, having one end positioned in the path of movement of the closed inner end of the bellows and having its other end projecting beyond the flanged mouths of the tube and bellows.

2. In a thermostat, in combination: a thinwalled metal tube having a closed and an open end with a peripheral flange; a tubular, bellowstype, pressure responsive structure within said tube, having a closed inner end and an open end with a peripheral flange superimposed upon said tube flange; a separately formed collar of heavier material, having a hollow boss within which the open ends of said tubular members are disposed and having a broad flange upon which said tubular flange and bellows flange are superimposed in the order named; means to secure said ilanges together in fluid tight assemblage, whereby a fluid pressure chamber is formed between the inner walls of said tube and the exterior walls of said bellows, said chamber being adapted to receive a temperature responsive fluid which serves to exert a lengthwise acting collapsing force upon said bellows structure when the temperature of said fluid rises; and a rod within said bellows, having one end positioned in the path of movement of the closed inner end of the bellows and having its other end projecting beyond the'nanged mouths of the tube and bellows; said device being further characterized by a supporting structure upon which said device is mounted, al'so by terminals for an electrical circuit and by an electrical switch in circuit with said terminals, all mounted on said supporting structure and operable mechanically by said rod, whereby said thermostat is adapted to control said electrical circuit, said electrical switch constituting a unitary structure adapted for removable assembly with said support, and bolts transiixing said collar flange, said support and a suitable part of said switch, to fasten said tube. bellows and switch in assembled relation with said support.

3. In a thermostat, in combination: a thinwalled metal tube having a closed end and an open end with a peripheral flange; a tubular, bellows-type, pressure responsive structure within said tube. having a closed inner end and an open end with a peripheral flange superimposed upon said tube fiange;'a separately formed collar of heavier material, having a hollow boss within which the open ends of said tubular members are disposed and having a broad flange upon which said tubular flange and bellows flange are superimposed'in the order named; means to secure said flanges together in fluid-tight assemblage, whereby a fluid pressure chamber is formed between the inner walls of said tube and the exterior walls of said bellows, said chamber being adapted to receive a temperature responsive fluid which serves to exert a lengthwise acting collapsing force upon said bellows structure when the temperature of said fluid rises; and a rod within said bellows, having one end positioned in the path of movement of the closed inner end of the bellows and having its other end projecting beyond the anged mouths of the tube and bellows; said device being further characterized by'a supporting structure upon which said device is mounted, a coil spring on said rod and bearing at one end against said supporting structure, being adapted to bias said rod in opposition to said collapsing force, said device being also characterized by a collar adjustable lengthwise on said rod to serve as a movable abutment for the other.

end of said spring, thereby to vary the strength of said bias.

4. In a thermostat, in combination: a thinwalled metal tube having a closed end and an open end with a peripheral flange; a tubular, bellows-type, pressure-responsive structure within said tube, having a closed inner end and an open end with a peripheral ange superimposed upon said tube flange; a separately formed collar of heavier material, having a hollow boss within which the open ends of said tubular members are' disposed and having a broad flange upon which said tubular flange and bellows flange are superimposed in the order named; means to secure said anges together in fluid-tight assemblage, Whereby a fluid pressure chamber is formed between the inner walls of said tube and the exterior walls of said bellows, said chamber being adapted to receive a temperature responsive fluid which serves to exert a lengthwise acting collapsing force upon said bellows structure when the temperature of said uid rises; and a rod within said bellows, having one end positioned in the path of movement of the closed inner end of the bellows and having its other end projecting beyond the flanged mouths of the tube and bellows; said device being further characterized by a supporting structure upon which said device is mounted, and also characterized by an electrical circuit controlling switch having an electrical contact member spring-biased to open position, and a latch spring-biased independently to a position for holding said contact member normally in circuit closing position. said parts being respectively mounted on said support with a part of said latch in position to be tripped mechanically by said rod when moved by the bellows, operated by thermo-responsive conditioning of the fluid in the fluid pressure chamber.

5. A thermostatic device comprising, in combination: an apertured'supporting panel; a thermostat mounted thereon, including a temperature-responsive fluid-pressure chamber with an enclosed pressure-responsive bellows structure and an axially disposed rod within said bellows, said thermostat being chiefly positioned upon one side of said panel and said rod being movable through the panel aperture by pressure-induced 5 `frame mounted upon said panel oppositesaid panel aperture. an electrical switch contact-lever and a restraining-latch for said lever. both mounted pivotally upon said frame; and a series of springs respectively seated'upon said frame 10 and biasing said rod. contact lever and latch independentLv, one spring tending to move the latch into position. to hold the contact lever in closed position, another spring tending to throw the switch lever to open the circuit when the latch 15 is thrown c!! by the rod, and a third spring acting to move the rod in opposition to collapsing movement of the bellows.

6. A thermostatic device comprising,k in ccmbination: an apertured supporting panel, a ther- 20 mostat mounted thereon, including a tempera- Y ture-responsive duid-pressure chamber with an enclosed pressure responsive bellows and an axially disposed rod within said bellows, said thermostat being chieily positioned upon one side oi said panel. and said rod being movable through the panel aperture by pressure-induced collapse oi said bellows, and a means upon the other-side of said panel forutranslating usefully said movement ot said rod; said translating means including an adjustable collar upon said rod, a frame mounted upon said panel opposite said panel aperture, an electrical switch contact-lever and a restraining latch for said lever, both mounted pivotally upon said trame; and a series oi' springs respectively seated von said frame and biasing said contact lever and latch independently. one spring tending to move the latch into position to hold the contact lever in closed position, another spring tending to throw the switch lever to open the circuit when the latch is thrown o!! by the vrod, and a third spring acting to move the rod in opposition to collapsing movement o! the bellows; and a push button for manually closing said switch and concurrently resetting said latch in its restraining position.

ROBERT J. PARSONS. 

